1,2,4-oxadiazole derivatives and their use as parasiticides for animals

ABSTRACT

The invention relates to 1,2,4-oxadiazole derivatives of the formula (I) ##STR1## in which R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , X, Y, m and n have the meanings given in the description, 
     to a plurality of processes for their preparation, and to their use as pesticides.

This application is a 371 of PCT/EP95/00024 filed Jan. 4, 1995.

The invention relates to new 1,2,4-oxadiazole derivatives, to aplurality of processes for their preparation, and to their use forcombating animal pests.

A range of substituted 1,2,4-oxadiazole derivatives have already beendisclosed as compounds for use in the control of parasitic protozoans(cf. EP 7 529, EP 8 356), as analgesics (GB 1 198 726) or as herbicides(JP 57 175 177) (cf. also the earlier, but not published, PatentApplication DE-P 42 32 418 by the Applicant Company).

Furthermore, the preparation of substituted 1,2,4-oxadiazolederivatives, such as, for example,5-(4-chlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazole and5-(2,4-dichlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazoleis described (J. Heterocycl. Chem., 15 (8), 1373-8, 1978). However, itsuse for combating animal pests has not been disclosed.

New 1,2,4-oxadiazole derivatives have now been found, of the formula (I)##STR2## in which R¹ represents halogen, alkyl or alkoxy,

R² represents hydrogen, halogen, halogenoalkyl or halogenoalkoxy,

R³ represents hydrogen or alkyl,

R⁴ represents hydrogen or alkyl,

R⁵ represents halogen, trialkylsilylalkyl, trialkylsilylalkoxy;

or a group --A_(k) --R⁷

in which

A represents oxygen, sulfur, SO, SO₂, alkylene, alkyleneoxy,alkylenethio, oxyalkylene, oxyalkyleneoxy, alkyleneoxyalkylene,alkenediyl or alkindiyl,

k represents a number 0 or 1,

R⁷ represents alkyl, halogenoalkyl, alkenyl, halogenoalkenyl, alkinyl,halogenoalkinyl, optionally substituted cycloalkyl, optionallysubstituted phenyl or optionally substituted pyridyl, or

R⁵ represents optionally substituted cycloalkyl, it being possible forone or two CH₂ groups which are not bonded directly to each other to bereplaced by oxygen and/or sulfur,

R⁶ represents hydrogen, halogen, alkyl, halogenoalkyl, alkoxy orhalogenoalkoxy,

m represents a number 1, 2 or 3,

n represents a number 1, 2 or 3,

x represents O, S, SO, SO₂, CH₂ or a group N--R⁸

in which

R⁸ represents hydrogen or alkyl and

Y represents a nitrogen atom or the group C--R⁹

in which

R⁹ represents hydrogen, halogen or alkyl;

with the exception of the compounds:

5-(4-chlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazole and5-(2,4-dichlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazole(cf. J. Heterocycl. Chem. 15 (8), 1373-8, 1978) and3-(4-tert-butyl-phenoxymethyl)-5-(2,6-difluorophenyl)-1,2,4-oxadiazole(cf. DE-P 42 32 418).

Depending on the nature of the substituents, the compounds of theformula (I) can exist in the form of geometric and/or optical isomers orvariously composed isomer mixtures. The invention relates to the pureisomers as well as to the isomer mixtures.

Furthermore, it has been found that the new 1,2,4-oxadiazole derivativesof the formula (I) are obtained when

a) compounds of the formula (II) ##STR3## in which n, X, R³, R⁴, R⁵ andR⁶ have the abovementioned meanings

are reacted with carboxylic acid derivatives of the formula (III), (IV)or (V) ##STR4## in which R¹, R², m and Y have the abovementionedmeanings,

R represents alkyl, preferably methyl or ethyl, and

Z represents a suitable leaving group such as, for example, halogen, or

b) compounds of the formula (VI) ##STR5## in which X, Y, R¹, R², R³, R⁴,R⁵, R⁶, m and n have the abovementioned meanings

are subjected to a cyclization reaction, if appropriate in the presenceof a diluent and if appropriate in the presence of a reaction auxiliary,or

c) compounds of the formula (VII) ##STR6## in which R¹, R², R³, R⁴, Yand m have the abovementioned meanings and

Z represents a suitable leaving group are reacted with compounds of theformula (VIII) ##STR7## in which X, R⁵, R⁶ and n have the abovementionedmeanings, in the presence of a diluent and, if appropriate, in thepresence of a reaction auxiliary.

Furthermore, it has been found that the new 1,2,4-oxadiazole derivativesof the formula (I) are highly suitable for combating animal pests. Inparticular, they are distinguished by a powerful activity againstarthropods and nematodes.

Surprisingly, the new 1,2,4-oxadiazole derivatives of the formula (I)according to the invention show considerably better activity againstanimal pests than the prior art compounds which have a similarconstitution.

Formula (I) provides a general definition of the compounds according tothe invention.

Preferred substituents or ranges of the radicals mentioned in theformulae hereinabove and hereinbelow are illustrated in the followingtext:

R¹ preferably represents fluorine, chlorine, bromine, C₁ -C₆ -alkyl orC₁ -C₆ -alkoxy.

R² preferably represents hydrogen, fluorine, chlorine, bromine, C₁ 14 C₆-halogenoalkyl or C₁ -C₆ -halogenoalkoxy.

R³ preferably represents hydrogen or C₁ -C₄ -alkyl.

R⁴ preferably represents hydrogen or C₁ -C₄ -alkyl.

R⁵ preferably represents fluorine, chlorine, bromine, tri-(C₁ -C₈-)-alkyl-silyl-(C₁ -C₆ -)-alkyl or tri-(C₁ -C₈ -)-alkyl-silyl-(C₁ -C₆-)-alkoxy; or a group --A_(k) --R⁷,

in which

A represents oxygen, sulfur, SO, SO₂, C₁ -C₆ -alkylene, C₁ -C₆-alkyleneoxy, C₁ -C₆ -alkylenethio, C₁ -C₆ -oxyalkylene, C₁ -C₆-oxyalkyleneoxy, C₁ -C₆ -alkyleneoxy-C₁ -C₆ -alkylene, C₂ -C₅-alkenediyl or C₂ -C₅ -alkindiyl,

k represents a number 0 or 1 and

R⁷ represents C₁ -C₂₀ -alkyl, C₂ -C₂₀ -alkenyl or C₂ -C₂₀ -alkinyl, eachof which is optionally monosubstituted or polysubstituted by fluorineand/or chlorine, or represents C₃ -C₁₂ -cycloalkyl which is optionallymonosubstituted to tri-substituted by identical or differentsubstituents and in which one or two CH₂ groups which are not directlyadjacent are optionally replaced by oxygen and/or sulfur, or phenylwhich is optionally monosubstituted to penta-substituted by identical ordifferent substituents or pyridyl which is optionally monosubstituted totrisubstituted by identical or different substituents, cycloalkyl,phenyl or pyridyl substituents which may be mentioned in each casebeing:

halogen,

C₁ -C₁₈ -alkyl,

C₁ -C₈ -alkoxy-C₁ -C₈ -alkyl,

C₁ -C₈ -halogenoalkoxy,

C₁ -C₄ -halogenoalkyl,

C₁ -C₁₈ -alkoxy which is optionally interrupted by a further 1-3 oxygenatoms,

C₁ -C₁₈ -alkylthio,

C₁ -C₈ -halogenoalkylthio,

3,4-difluoromethylene dioxo,

3,4-tetrafluoroethylene dioxo,

benzyliminooxymethyl which is optionally substituted by C₁ -C₄ -alkyl,C₃ -C₆ -cycloalkyl and/or halogen,

cyclohexyl and cyclohexyloxy, each of which is optionally substituted byC₁ -C₆ -alkyl, C₁ -C₆ -alkoxy, cyclohexyl and/or phenyl;

alkoxy, pyridyloxy which is optionally monosubstituted or disubstitutedby identical or different substituents from the series consisting ofhalogen, C₁ -C₄ -alkyl or C₁ -C₄ -halogenoalkyl;

phenyl, benzyl, phenoxy, phenylthio, benzyloxy and benzylthio, each ofwhich is optionally monosubstituted or disubstituted by identical ordifferent substituents from the series consisting of C₁ -C₁₂ -alkyl,halogen, C₁ -C₄ -halogenoalkyl, C.sub. -C₆ -alkoxy, C₁ -C₆-halogenoalkoxy, C₁ -C₆ -alkoxy-C₁ -C₆ -alkyl, C₁ -C₆-alkoxyethyleneoxy, C₁ -C₆ -alkylthio or C₁ -C₆ -halogenoalkylthio; or

R⁵ preferably represents optionally substituted C₃ -C₁₀ -cycloalkyl inwhich one or two CH₂ groups which are not directly linked to each otherare replaced by oxygen and/or sulfur, suitable substituents being thecycloalkyl substituents mentioned in the case of R⁷.

R⁶ preferably represents hydrogen, fluorine, chlorine, bromine, C₁ -C₈-alkyl, C₁ -C₈ -halogenoalkyl, C₁ -C₈ -alkoxy or C₁ -C₈ -halogenoalkoxy.

m preferably represents a number 1, 2 or 3.

n preferably represents a number 1, 2 or 3.

X preferably represents O, S, SO₂, CH₂ or the group NH or N--CH₃.

Y preferably represents nitrogen or the group --CR⁹

in which

R⁹ represents hydrogen, fluorine, chlorine, bromine or C₁ -C₆ -alkyl.

R¹ particularly preferably represents fluorine, chlorine, bromine, C₁-C₄ -alkyl or C₁ -C₄ -alkoxy.

R² particularly preferably represents hydrogen, fluorine, chlorine,bromine, C₁ -C₄ -halogenoalkyl or C₁ -C₄ -halogenoalkoxy.

R³ particularly preferably represents hydrogen or methyl.

R⁴ particularly preferably represents hydrogen or methyl.

R⁵ particularly preferably represents fluorine, chlorine, bromine,trimethylsilylmethyl, trimethylsilylmethoxy, dimethylethylsilylmethyl,dimethylethylsilylmethoxy, butyldimethylsilylmethyl,butyldimethylsilylmethoxy

or a group --A_(k) --R⁷

in which

A represents oxygen, sulfur, SO, SO₂ or C₁ -C₄ -alkylene, C₁ -C₄-alkyleneoxy, C₁ -C₄ -alkylenethio, C₁ -C₄ -oxyalkylene, C₁ -C₄-oxyalkyleneoxy, C₁ -C₄ -alkyleneoxy-C₁ -C₄ -alkylene, in particular--CH₂ --, --CH₂ CH₂ --, --CH(CH₃)--, --CH₂ CH₂ CH₂ --, --CH(CH₃)CH₂ --,--C(CH₃)₂₋₋, --CH₂ CH₂ CH₂ CH₂ --, --CH(CH₃)CH₂ CH₂ --, --CH₂ CH(CH₃)CH₂--, --CH₂ O--, --CH₂ CH₂ O--, --CH(CH₃)--, --CH₂ CH₂ CH₂ O--,--CH(CH₃)CH₂ O--, --C(CH₃)O--, --CH₂ CH₂ CH₂ CH₂ O--, --CH(CH₃)CH₂ CH₂O--, --CH₂ CH(CH₃)CH₂ O--, --OCH₂ --, --CH₂ S--, --OCH₂ CH₂ --,--OCH(CH₃)--, --OCH₂ CH₂ CH₂ --, --OCH(CH₃)CH₂ --, --OC(CH₃)₂ --, --OCH₂CH₂ CH₂ CH₂ --, --OCH(CH₃)CH₂ CH₂ --, --OCH₂ CH(CH₃)CH₂ --, --CH₂ OCH₂--, --CH₂ SCH₂ --, --CH₂ OCH₂ CH₂ --, --OCH₂ O--, --OCH₂ CH₂ O--,--OCH(CH₃)O--, --OCH₂ CH₂ CH₂ O--, --OCH(CH₃)CH₂ O--, --OC(CH₃)₂ O--,--OCH₂ CH₂ CH₂ CH₂ O--, --OCH(CH₃)CH₂ CH₂ O-- and --CH₂ CH(CH₃)CH₂ O--or C₂ -C₅ -alkenediyl or C₂ -C₅ -alkindiyl,

k represents a number 0 or 1 and

R⁷ represents C₁ -C₂₀ -alkyl, C₂ -C₂₀ -alkenyl or C₂ -C₂₀ -alkinyl, eachof which is optionally monosubstituted or polysubstituted by fluorineand/or chlorine, in particular ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, isoamyl, neopentyl, n-hexyl,isohexyl, 3,3-dimethylbutyl, n-heptyl, 5-methylhexyl, 4-methylhexyl,3-methylhexyl, 4,4-dimethylpentyl, n-octyl, 6-methylheptyl, n-nonyl,7-methyloctyl, n-decyl, 8-methylnonyl, n-undecyl, 9-methyldecyl,n-dodecyl, 10-methylundecyl, n-undecyl, 9-methyldecyl, n-dodecyl,10-methylundecyl, n-tridecyl, 11-methyldodecyl, n-tetradecyl,12-methyltridecyl, n-pentadecyl, 13-methyl-tetradecyl, n-hexadecyl,n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, vinyl, propenyl,isopropenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl,3-methyl-1-butenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl,3,3-dimethyl-1-butynyl, 4-methyl-1-pentynyl, 3-methyl-1-pentynyl,5-methyl-1-hexynyl, 4-methyl-1-hexynyl, 3-methyl-1-hexynyl, octynyl,nonynyl, decynyl, undecynyl, dodecynyl, tridecynyl, tetradecynyl,pentadecynyl and hexadecynyl, each of which is optionallymonosubstituted or polysubstituted by fluorine and/or chlorine; C₃ -C₁₀-cycloalkyl which is optionally monosubstituted to trisubstituted byidentical or different substituents, in particular cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl, phenylwhich is optionally monosubstituted to pentasubstituted by identical ordifferent substituents, or pyridyl which is optionally monosubstitutedto trisubstituted by identical or different substituents; suitablecycloalkyl, phenyl and pyridyl substituents which may be mentioned ineach case being:

F, Cl, Br,

C₁ -C₁₈ -alkyl,

C₁ -C₆ -alkoxy-C₁ -C₈ -alkyl,

C₁ -C₈ -alkoxy which is monosubstituted to hexasubstituted by identicalor different substituents from the series consisting of F and Cl,

C₁ -C₂ -alkyl which is monosubstituted to pentasubstituted by identicalor different substituents from the series consisting of F and Cl,

C₁ -C₁₈ -alkoxy,

(OCH₂ H₄)₁₋₃ --O--C₁ -C₆ -alkyl,

C₁ -C₁₂ -alkylthio,

C₁ -C₈ -alkylthio which is monosubstituted to hexasubstituted byidentical or different substituents from the series consisting of F

and Cl,

3,4-difluoromethylenedioxo,

3,4-tetrafluoroethylenedioxo, the groups ##STR8## cyclohexyl andcyclohexyloxy, each of which is optionally substituted by C₁ -C₄ -alkyl,C₁ -C₄ -alkoxy, cyclohexyl or phenyl;

pyridyloxy which is optionally monosubstituted or disubstituted byidentical or different substituents from the series consisting of F, Cland CF₃,

phenyl, benzyl, phenoxy, phenylthio, benzyloxy and benzylthio, each ofwhich is optionally monosubstituted or disubstituted by identical ordifferent substituents from tiLe series consisting of

C₁ -C₁₂ -alkyl, F, Cl, Br, CF₃, C₁ -C₄ -alkoxy, C₁ -C₄ -alkoxy which ismonosubstituted to hexasubstituted by identical or differentsubstituents from the series consisting of F and Cl, C₁ -C₄ -alkoxy-C₁-C₄ -alkyl, C₁ -C₄ -alkoxyethyleneoxy, C₁ -C₄ -alkylthio or C₁ -C₄-alkylthio which is monosubstitutued to hexasubstituted by identical ordifferent substituents from the series consisting of F and Cl, or

R⁵ particularly preferably represents optionally substituted C₃ -C₈-cycloalkyl in which one or two CH₂ groups which are not linked to eachother are replaced by oxygen and/or sulfur, suitable substituents beingthose mentioned in the case of R⁷,

R⁶ particularly preferably represents hydrogen, fluorine, chlorine,bromine, C₁ -C₆ -alkyl, C₁ -C₆ -halogenoalkyl, C₁ -C₆ -alkoxy or C₁ -C₆-halogenoalkoxy.

m particularly preferably represents a number 1, 2 or 3.

n particularly preferably represents a number 1 or 2.

X particularly preferably represents O, S, SO, SO₂, CH₂ or the group NHor N--CH₃.

Y particularly preferably represents a nitrogen atom or the group --CR⁹

in which

R⁹ represents hydrogen, fluorine, chlorine, bromine or C₁ -C₆ -alkyl.

Very particularly preferred compounds of the formula (I-1) ##STR9## arethose in which A represents one of the radicals mentioned below##STR10## B represents one of the radicals ##STR11## R³ representshydrogen or methyl, X represents CH₂, O, S, SO or SO₂, and

R⁵ has the abovementioned meaning.

The compounds5-(4-chlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazole,(2,4-dichlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazoleand3-(4-tert-butyl-phenoxymethyl)-5-(2,6-difluorophenyl)-1,2,4-oxadiazoleare in each case excepted.

Unless otherwise specified, alkyl radicals, also in connection withhetero atoms such as, for example, in alkoxy or alkylthio, are in eachcase straight-chain or branched as far as this is possible. In the eventthat n=2, the radicals R⁶ can be identical or different. In the eventthat m>1, the radicals R² can be identical or different.

The definitions of radicals can be combined as desired, that is to saycombinations between the preferred and particularly preferred ranges arealso possible. Preferred compounds of the formula (I) are those in whichR¹, R², R³, R⁴, R⁵, R⁶, Y, m and n have the meanings given as beingpreferred.

Preferred compounds of the formula (I) are those in which R¹, R², R³,R⁴, R⁵, R⁶, Y, m and n have the meanings given as being particularlypreferred.

Examples of compounds of the formula (I-1) according to the inventionare listed in Tables 1-10. ##STR12##

                                      TABLE 1                                     __________________________________________________________________________    A        CH--R.sup.3                                                                        X                                                                                2                                                            __________________________________________________________________________    1 #STR13##                                                                             CH.sub.2                                                                           O                                                                                3 #STR14##                                                   1 #STR15##                                                                             CH.sub.2                                                                           O                                                                                4 #STR16##                                                   1 #STR17##                                                                             CH.sub.2                                                                           O                                                                                5 #STR18##                                                   1 #STR19##                                                                             CH.sub.2                                                                           O                                                                                6 #STR20##                                                   1 #STR21##                                                                             CH.sub.2                                                                           O                                                                                7 #STR22##                                                   1 #STR23##                                                                             CH.sub.2                                                                           O                                                                                8 #STR24##                                                   1 #STR25##                                                                             CH.sub.2                                                                           O                                                                                9 #STR26##                                                   1 #STR27##                                                                             CH.sub.2                                                                           O                                                                                0 #STR28##                                                   1 #STR29##                                                                             CH.sub.2                                                                           O                                                                                1 #STR30##                                                   1 #STR31##                                                                             CH.sub.2                                                                           O                                                                                2 #STR32##                                                   1 #STR33##                                                                             CH.sub.2                                                                           O                                                                                3 #STR34##                                                   1 #STR35##                                                                             CH.sub.2                                                                           O                                                                                4 #STR36##                                                   1 #STR37##                                                                             CH.sub.2                                                                           O                                                                                5 #STR38##                                                   1 #STR39##                                                                             CH.sub.2                                                                           O                                                                                6 #STR40##                                                   1 #STR41##                                                                             CH.sub.2                                                                           O                                                                                7 #STR42##                                                   1 #STR43##                                                                             CH.sub.2                                                                           O                                                                                8 #STR44##                                                   1 #STR45##                                                                             CH.sub.2                                                                           O                                                                                9 #STR46##                                                   1 #STR47##                                                                             CH.sub.2                                                                           O                                                                                0 #STR48##                                                   1 #STR49##                                                                             CH.sub.2                                                                           O                                                                                1 #STR50##                                                   1 #STR51##                                                                             CH.sub.2                                                                           O                                                                                2 #STR52##                                                   1 #STR53##                                                                             CH.sub.2                                                                           O                                                                                3 #STR54##                                                   1 #STR55##                                                                             CH.sub.2                                                                           O                                                                                4 #STR56##                                                   1 #STR57##                                                                             CH.sub.2                                                                           O                                                                                5 #STR58##                                                   1 #STR59##                                                                             CH.sub.2                                                                           O                                                                                6 #STR60##                                                   1 #STR61##                                                                             CH.sub.2                                                                           O                                                                                7 #STR62##                                                   1 #STR63##                                                                             CH.sub.2                                                                           O                                                                                8 #STR64##                                                   1 #STR65##                                                                             CH.sub.2                                                                           O                                                                                9 #STR66##                                                   1 #STR67##                                                                             CH.sub.2                                                                           O                                                                                0 #STR68##                                                   1 #STR69##                                                                             CH.sub.2                                                                           O                                                                                1 #STR70##                                                   1 #STR71##                                                                             CH.sub.2                                                                           O                                                                                2 #STR72##                                                   1 #STR73##                                                                             CH.sub.2                                                                           O                                                                                3 #STR74##                                                   1 #STR75##                                                                             CH.sub.2                                                                           O                                                                                4 #STR76##                                                   1 #STR77##                                                                             CH.sub.2                                                                           O                                                                                5 #STR78##                                                   1 #STR79##                                                                             CH.sub.2                                                                           O                                                                                6 #STR80##                                                   1 #STR81##                                                                             CH.sub.2                                                                           O                                                                                7 #STR82##                                                   1 #STR83##                                                                             CH.sub.2                                                                           O                                                                                9 #STR84##                                                   1 #STR85##                                                                             CH.sub.2                                                                           O                                                                                0 #STR86##                                                   __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                        Compounds of Table 1 in which                                                 8 #STR87##                                                                    ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Compounds of Table 1 in which                                                 1 #STR88##                                                                    ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Compounds of Table 1 in which                                                 2 #STR89##                                                                    ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        Compounds of Table 1 in which                                                 3 #STR90##                                                                    ______________________________________                                    

                  TABLE 6                                                         ______________________________________                                        Compounds of Table 1 in which                                                 4 #STR91##                                                                    ______________________________________                                    

Table 7

Compounds of Tables 1-6 in which X=S;

Table 8

Compounds of Tables 1-6 in which X=CH₂ ;

Table 9

Compounds of Tables 1-6 in which X=NH;

Table 10

Compounds of Tables 1-9 in which --CH--R³ =--CH--CH₃.

If, for example, 3-chloro-2-methyl-phenoxy-acetamide oxime and1,3-difluoro-2-(triethoxymethyl)-benzene are used for carrying outprocess a) according to the invention, the course of the reaction can berepresented by the following equation: ##STR92##

Formula (II) provides a general definition of the amide oximes requiredas starting substances for carrying out process a) according to theinvention. In this formula, X, R³, R⁴, R⁵, R⁶ and n preferably representthose radicals which have already been mentioned in connection with thedescription of the substances of the formula (I) according to theinvention as being preferred for these substituents.

The compounds of the formula (II), which are used as starting materials,are known in some cases (cf. for example Cervena' et al. Collect. Czech.Chem. Commun. 46 (1981) 5, pp. 1188-1198, EP 8 356, EP 7 529) or can beobtained by the processes described therein.

They are obtained, for example, when compounds of the formula (IX)##STR93## in which R³, R⁴, R⁵, R⁶ and n have the abovementionedmeanings, are reacted with hydroxyl amine or a salt thereof, such as,for example, hydroxylamine hydrochloride, at temperatures between 0° C.and 150° C., preferably between 20° C. and 100° C., if appropriate inthe presence of a base such as, for example, sodium carbonate and in thepresence of a diluent such as, for example, ethanol.

The compounds of the formula (IX) are known and/or can be prepared in asimple manner by customary processes. The compounds of the formula (IX)are obtained, for example, by reacting suitable phenols or anilines witha substituted acetonitrile, such as, for example, chloroacetonitrile, inthe presence of a base such as sodium carbonate, sodium hydride orsodium hydroxide and in the presence of a diluent such as, for example,acetone (cf. the preparation examples).

Formula (III) provides a general definition of the orthocarboxylatesfurthermore to be used as starting substances for carrying out processa) according to the invention. Formulae (IV) and (V) provide generaldefinitions of the carboxylic acid derivatives furthermore suitable forcarrying out process a) according to the invention. In formulae (III) to(V), R¹, R², Y and m have the meanings which have already been mentionedin connection with the description of the substances of the formula (I)according to the invention as being preferred for this substituent. Informula (V), Z has the meaning of a suitable leaving group such as, forexample, halogen or alkoxy. The orthocarboxylates of the formula (III)and the carboxylates of the formulae (IV) and (V) are generally knowncompounds of organic chemistry.

The compounds of the formulae (II) and (III) are preferably employed inthe presence of an acidic catalyst. Suitable acidic catalysts arevirtually all mineral acids or Lewis acids. The mineral acids preferablyinclude hydrohalic acids, such as hydrofluoric acid, hydrochloric acid,hydrobromic acid or hydroiodic acid, and also sulfuric acid, phosphoricacid, phosphorous acid, nitric acid, and the Lewis acids preferablyinclude aluminum(III) chloride, boron trifluoride or its etherate,titanium(IV) chloride and tin(IV) chloride.

The following Lewis acids are particularly preferably employed:

boron trifluoride or its etherate, aluminum(III) chloride.

When employing the compounds of the formula (III), process a) isgenerally carried out in such a manner that compounds of the formula(II) are combined with an excess of compounds of the formula (III) andthe mixture is heated in the presence of an acidic catalyst. Compound(III) acts simultaneously as the diluent. The reaction time isapproximately 1 to 4 hours. The reaction is carried out at temperaturesbetween +20° C. and +200° C., preferably between +100° C. and +155° C.It is preferably carried out under the pressure which is establishedunder the reaction conditions when the mixture is heated to the reactiontemperature required.

The compounds of the formulae (II) are preferably reacted with thecompounds of the formulae (IV) or (V) in the presence of a base.Suitable bases are all customary acid acceptors. The following canpreferably be used:: tertiary amines, such as triethylamine, pyridine,diazabicyclooctane (DABCO), diazabicycloundecane (DBU),diazabicyclonones (DBN), Hunig base and N,N-dimethylaniline, furthermorealkaline earth metal oxides, such as magnesium oxide and calcium oxide,and moreover alkali metal carbonates and alkaline earth metalcarbonates, such as sodium carbonate, potassium carbonate and calciumcarbonate.

The reaction of the compounds of the formula (II) with the compounds ofthe formulae (IV) or (V) is generally carried out in the presence of adiluent.

Diluents which can be employed are all solvents which are inert to thesecompounds. The following can preferably be used: hydrocarbons, such asbenzine, benzene, toluene, xylene and tetraline, furthermorehalogenohydrocarbons, such as methylene chloride, chloroform, carbontetrachloride, chlorobenzene and o-dichlorobenzene, moreover ketones,such as acetone and methyl isopropyl ketone, additionally ethers, suchas diethyl ether, tetrahydrofuran and dioxane, in addition carboxylates,such as ethyl acetate, and also strongly polar solvents, such asdimethyl sulfoxide and sulfolane. If the acid halide is sufficientlystable to hydrolysis, the reaction can also be carried out in thepresence of water.

When employing the compounds of the formula (IV) or (V), process a) isgenerally carried out in such a manner that compounds of the formula(II) are stirred with an equimolar amount or an excess of the compoundof the formula (IV) or (V) at temperatures between -20° C. and 150° C.,preferably between 0° C. and 100° C., in the presence of a diluent andin the presence of an at least equimolar amount of base until thereaction has ended.

When the reaction is complete, the reaction mixture is cooled andconcentrated in vacuo, and the residue which remains is taken up in anorganic solvent and processed in a manner known per se. The productsobtained can be purified in the customary manner by recrystallization,distillation in vacuo or column chromatography (cf. also the preparationexamples).

If, in process b), O-(2,6-difluorobenzoyl)-4-n-heptyl-phenoxy-acetamideoxime is employed as starting compound of the formula (VI), the processcan be described by the following equation: ##STR94##

Preferred compounds of the formula (VI) which are employed in process b)are those in which X and the radicals R¹, R², R³, R⁴, R⁵, R⁶, n, m and Yhave the meanings mentioned in the case of the compounds of the formula(I) as being preferred and particularly preferred.

The compounds of the formula (VI) are new and also are subject of theinvention. They can originate in situ in process a) from compounds ofthe formula (II) and suitable carboxylic acid derivatives of theformulae (IV) and (V), but can also be employed in the isolated form, asis the case in process b).

Some of the compounds of the formula (VI) themselves havearthropodicidal or nematicidal properties.

The cyclization of the compounds of the formula (VI) is preferablycarried out using diluents and, if appropriate, in the presence of areaction auxiliary.

Diluents for carrying out process b) according to the invention are allinert organic solvents.

Examples which may be mentioned are: halogenohydrocarbons, in particularchlorohydrocarbons such as tetrachloroethylene, tetrachloroethane,dichloropropane, methylene chloride, dichlorobutane, chloroform, carbontetrachloride, trichloroethane, trichloroethylene, pentachloroethane,difluorobenzene, 1,2-dichloroethane, chlorobenzene, dichlorobenzene,chlorotoluene, trichlorobenzene; alcohols such as methanol, ethanol,isopropanol, butanol; ethers, such as ethyl propyl ether,methyl-tert-butyl ether, n-butyl ether, di-n-butyl ether, di-isobutylether, di-iso-amyl ether, di-isopropyl ether, anisole, phenetol,cyclohexyl methyl ether, diethyl ether, ethylene glycol dimethyl ether,tetrahydrofuran, dioxane, dichlorodiethyl ether, nitrohydrocarbons, suchas nitromethane, nitroethane, nitrobenzene, chloronitrobenzene,o-nitrotoluene; nitriles such as acetonitrile, butyronitrile,isobutyronitrile, benzonitrile, m-chlorobenzonitrile; aliphatic,cycloaliphatic or aromatic hydrocarbons such as heptane, hexane, nonane,cymene, benzine fractions within a boiling range of 70° C. to 190° C.,cyclohexane, methylcyclohexane, petroleum ether, ligroin, octane,benzene, toluene, xylene; esters such as ethyl acetate, isobutylacetate; amides, for example formamide, N-methyl ethyl ketone,carboxylic acids such as acetic acid, propionic acid, butyric acid.Mixtures of the abovementioned solvents and diluents are also suitable.

Carboxylic acids, such as acetic acid, or aromatic hydrocarbons, such astoluene and xylene, are preferred.

Substances which can be used as reaction auxiliaries are all suitabledehydrating agents such as, for example, dicyclohexylcarbodiimide [DCC](cf., for example, F. Eloy Fortschr. chem. Forsch. 4 (1965) p. 807).

Process b) is generally carried out in such a manner that compounds ofthe formula (VI) are heated in a suitable diluent, if appropriate in thepresence of a suitable reaction auxiliary. The reaction time isapproximately 1 to 10 hours. The reaction is carried out at temperaturesbetween +20° C. and +200° C., preferably between +70° C. and +170° C.The process is preferably carried out under the pressure which isestablished under the reaction conditions when the mixture is heated atthe reaction temperature required.

When the reaction is complete, the reaction mixture is cooled, theentire reaction batch is concentrated, and the product is taken up in anorganic solvent and processed in a manner known per se. The productsobtained can be purified in the customary manner by recrystallization,distillation in vacuo or column chromatography (cf. also the preparationexamples).

If, in process c) for the preparation of the new 1,2,4-oxadiazolederivatives of the formula (I),3-chloromethyl-5-(2,6-difluoro-phenyl)-1,2,4-oxadiazole is employed asthe compound of the formula (VII) and4-(4-trifluoromethyl-phenoxy)-phenol as compound of the formula (VIII),the process can be represented by the following equation: ##STR95##

Formula (VII) provides a general definition of the 3,5-disubstituted1,2,4-oxadiazoles required as starting substances for carrying outprocess c) according to the invention. In this formula, Y, R¹, R², R³,R⁴ and m preferably represent those radicals which have already beenmentioned in connection with the description of the substances of theformula (I) according to the invention as being preferred for thesesubstituents.

Z represents a suitable leaving group such as, for example, halogen,alkylsulfonyloxy or arylsulfonyloxy, such as chlorine, bromine,methanesulfonyloxy or toluenesulfonyloxy.

The compounds of the formula (VII) which are used as starting materialsare known in some cases (cf., for example, German Offenlegungsschrift 2406 786, GB 2 205 101; G. Palazzo J. Heterocyclic Chem. 16 (1979) p.1469) or can be obtained by the processes described therein.

Some of the compounds of the formula (VII) themselves havearthropodicidal or nematicidal properties.

The reaction of the compounds of the formula (VII) with the compounds ofthe formula (VIII) is preferably carried out in the presence of diluentsand in the presence of a basic reaction auxiliary.

Suitable diluents for carrying out process c) according to the inventionare all inert organic solvents, as they have already been mentioned inthe case of process b).

Substances which can be employed as basic reaction auxiliaries are allsuitable acid-binding agents such as amines, in particular tertiaryamines, and also alkali metal and alkaline earth metal compounds.

Examples which may be mentioned are the hydrides, hydroxides, oxides andcarbonates of lithium, sodium, potassium, magnesium, calcium and barium,furthermore other basic compounds such as trimethylamine,tribenzylamine, triisopropylamine, tributylamine, tribenzylamine,tricyclohexylamine, triamylamine, trihexylamine, N,N-dimethyl-aniline,N,N-dimethyl-toluidine, N,N-dimethyl-p-aminopyridine,N-methyl-pyrrolidine, N-methylpiperidine, N-methyl-imidazole,N-methyl-pyrrole, N-methyl-morpholine, N-methyl-hexamethyleneimine,pyridine, quinoline, α-picoline, β-picoline, isoquinoline, pyrimidine,acridine, N,N,N',N'-tetra-methylenediamine,N,N,N'N'-tetra-ethylenediamine, quinoxaline, N-propyl-diisopropylamine,N,N'-dimethyl-cyclohexylamine, 2,6-lutidine, 2,4-lutidine,triethylenediamine, diazabicyclooctane (DABCO), diazabicyclonone (DBN)or diazabicycloundecene (DBU).

Tertiary amines such as, for example, triethylamine, N-methyl-morpholineor heteroaromatics or hydrides or hydroxides of potassium or sodium arepreferably used.

Process c) is generally carried out in such a manner that compounds ofthe formula (VII) are combined with a small excess of compounds of theformula (VIII), if appropriate in the presence of a diluent, and themixture is heated in the presence of a basic reaction auxiliary. Thereaction time is approximately 5 to 30 hours. The reaction is carriedout at temperatures between +20° C. and +200° C., preferably between+70° C. and +170° C. The process is preferably carried out under thepressure which is established under the reaction conditions when themixture is heated at the reaction temperature required.

When the reaction is complete, the reaction mixture is cooled, theentire reaction batch is filtered, the filtrate is concentrated invacuo, and the crude product which remains is worked up in a mannerknown per se. The products obtained can be purified in the customarymanner by recrystallization, distillation in vacuo or, preferably, bycolumn chromatography (cf. also the preparation examples).

In those compounds of the formula (I) which have been synthesized byprocesses a) to c) which have an arylthiomethyl radical, the group whichhas sulfur attached to it can be oxidized. The oxidation can be carriedout by customary processes using suitable oxidants, such as peroxides(for example H₂ O₂), permanganate, perbenzoic acid, or a mixture ofpotassium peroxomonosulfate, 2 KHSO₅, KHSO₄, and a solvent or solventmixture (for example water, acetic acid, methanol) (cf. A. R. Katritzky,C. W. Rees in Comprehensive Heterocyclic Chemistry, Pergamon Press,Oxford, N.Y., 1984, Vol. 3, p. 96; D. J. Brown et al. Chem. Soc. (C),1971, p. 256). ##STR96##

The oxidation can also be initiated or accelerated by means ofcatalysts.

The active compounds are suitable for combating animal pests, preferablyarthropods and nematodes, and in particular insects and arachnids, whichare encountered in agriculture, in forestry, in the protection of storedproducts and of materials, and in the hygiene field. They are activeagainst normally sensitive and resistant species and against all or somestages of development. The abovementioned pests include:

From the order of the Isopoda, for example, Oniscus asellus,Armadillidium vulgare and Porcellio scaber.

From the order of the Diplopoda, for example, Blaniulus guttulatus.

From the order of the Chilopoda, for example, Geophilus carpophagus andScutigera spec.

From the order of the Symphyla, for example, Scutigerella immaculata.

From the order of the Thysanura, for example, Lepisma saccharina.

From the order of the Collembola, for example, Onychiurus armatus.

From the order of the Orthoptera, for example, Blatta orientalis,Periplaneta americana, Leucophaea maderae, Blattella germanica, Achetadomesticus, Gryllotalpa spp., Locusta migratoria migratorioides,Melanoplus differentialis and Schistocerca gregaria.

From the order of the Dermaptera, for example, Forficula auricularia.

From the order of the Isoptera, for example, Reticulitermes spp.

From the order of the Anoplura, for example, Phylloxera vastatrix,Pemphigus spp., Pediculus humanus corporis, Haematopinus spp. andLinognathus spp.

From the order of the Mallophaga, for example, Trichodectes spp. andDamalinea spp.

From the order of the Thysanoptera, for example, Hercinothrips femoralisand Thrips tabaci.

From the order of the Heteroptera, for example, Eurygaster spp.,Dysdercus intermedius, Piesma quadrata, Cimex lectularius, Rhodniusprolixus and Triatoma spp.

From the order of the Homoptera, for example, Aleurodes brassicae,Bemisia tabaci, Trialeurodes vaporariorum, Aphis gossypii, Brevicorynebrassicae, Cryptomyzus ribis, Aphis fabae, Doralis pomi, Eriosomalanigerum, Hyalopterus arundinis, Macrosiphum avenae, Myzus spp.,Phorodon humuli, Rhopalosiphum padi, Empoasca spp., Euscelis bilobatus,Nephotettix cincticeps, Lecanium corni, Saissetia oleae, Laodelphaxstriatellus, Nilaparvata lugens, Aonidiella aurantii, Aspidiotushederae, Pseudococcus spp. and Psylla spp.

From the order of the Lepidoptera, for example, Pectinophoragossypiella, Bupalus piniarius, Cheimatobia brumata, Lithocolletisblancardella, Hyponomeuta padella, Plutella maculipennis, Malacosomaneustria, Euproctis chrysorrhoea, Lymantria app., Bucculatrixthurberiella, Phyllocnistis citrella, Agrotis spp., Euxoa spp., Feltiaspp., Earias insulana, Heliothis app., Spodoptera exigua, Mamestrabrassicae, Panolis flammea, Prodenia litura, Spodoptera spp.,Trichoplusia ni, Carpocapsa pomonella, Pieris spp., Chilo spp., Pyraustanubilalis, Ephestia kuehniella, Galleria mellonella, Tineolabisselliella, Tinea pellionella, Hofmannophila pseudospretella, Cacoeciapodana, Capua reticulana, Choristoneura fumiferana, Clysia ambiguella,Homona magnanima and Tortrix viridana.

From the order of the Coleoptera, for example, Anobium punctatum,Rhizopertha dominica, Acanthoscelides obtectus, Bruchidius obtectus,Hylotrupes bajulus, Agelastica alni, Leptinotarsa decemlineata, Phaedoncochleariae, Diabrotica spp., Psylliodes chrysocephala, Epilachnavarivestis, Atomaria spp., Oryzaephilus surinamensis, Anthonomus spp.,Sitophiluis spp.,

Otiorrhynchus sulcatus, Cosmopolites sordidus, Ceuthorrhynchusassimilis, Hypera postica, Dermestes spp., Trogoderma spp., Anthrenusspp., Attagenus spp., Lyctus spp., Meligethes aeneus, Ptinus spp.,Niptus hololeucus, Gibbium psylloides, Tribolium spp., Tenebrio molitor,Agriotes spp., Conoderus spp., Melolontha melolontha, Amphimallonsolstitialis and Costelytra zealandica.

From the order of the Hymenoptera, for example, Diprion spp., Hoplocampaspp., Lasius spp., Monomoriuni pharaonis and Vespa spp.

From the order of the Diptera, for example, Aedes spp., Anopheles spp.,Culex spp., Drosophila melanogaster, Musca spp., Fannia spp., Calliphoraerythrocephala, Lucilia spp., Chrysomyia spp., Cuterebra spp.,Gastrophilus spp., Hyppobosca spp., Stomoxys spp., Oestrus spp.,Hypoderma spp., Tabanus spp., Tannia Spp., Bibio hortulanus, Oscinellafrit, Phorbia spp., Pegomyia hyoscyami, Ceratitis capitata, Dacus oleaeand Tipula paludosa.

From the order of the Siphonaptera, for example, Xenopsylla cheopis andCeratophyllus spp.

From the order of the Arachnida, for example, Scorpio maurus andLatrodectus mactans.

From the order of the Acarina, for example, Acarus siro, Argas spp.,Ornithodoros spp., Dermanyssus gallinae, Eriophyes ribis, Phyllocoptrutaoleivora, Boophilus spp., Rhipicephalus spp., Amblyomma spp., Hyalommaspp., Ixodes spp., Psoroptes spp., Chorioptes spp., Sarcoptes spp.,Tarsonemus spp., Bryobia praetiosa, Panonychus spp., Tetranychus spp.

The plant-parasitic nematodes include Pratylenchus spp., Radopholussimilis, Ditylenchus dipsaci, Tylenchulus semipenetrans, Heteroderaspp., Meloidogyne spp., Apelenchoides spp., Longidorus spp., Xiphinemaspp., Trichodorus spp.

The active compounds can be converted to the customary formulations,such as solutions, emulsions, suspensions, powders, dusts, pastes,soluble powders, granules, suspension-emulsion concentrates, natural andsynthetic materials impregnated with active compound, and very finecapsules in polymeric substances and in coating compositions for seed,and formulations used with burning equipment, such as fumigatingcartridges, fumigating cans, fumigating coils and the like, as well asULV cold mist and warm mist formulations.

These formulations are produced in a known manner, for example by mixingthe active compounds with extenders, that is liquid solvents and/orsolid carriers, optionally with the use of surface-active agents, thatis emulsifying agents and/or dispersing agents, and/or foam-formingagents.

In the case of the use of water as an extender, organic solvents can,for example, also be used as auxiliary solvents. As liquid solvents,there are suitable in the main: aromatics, such as xylene, toluene oralkylnaphthalenes, chlorinated aromatics or chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, forexample mineral oil fractions, mineral and vegetable oils, alcohols,such as butanol or glycol as well as their ethers and esters, ketones,such as acetone, methyl ethyl ketone, methyl isobutyl ketone orcyclohexanone, strongly polar solvents, such as dimethylformamide anddimethyl sulfoxide, as well as water; by liquefied gaseous extenders orcarriers are meant liquids which are gaseous at ambient temperature andunder atmospheric pressure, for example aerosol propellants, such ashalogenated hydrocarbons as well as butane, propane, nitrogen and carbondioxide; as solid carriers there are suitable: for example ammoniumsalts and ground natural minerals, such as kaolins, clays, talc, chalk,quartz, attapulgite, montmorillonite or diatomaceous earth, and groundsynthetic minerals, such as highly disperse silica, alumina andsilicates; as solid carriers for granules there are suitable: forexample crushed and fractionated natural rocks such as calcite, marble,pumice, sepiolite and dolomite, as well as synthetic granules ofinorganic and organic meals, and granules of organic material such assawdust, coconut shells, maize cobs and tobacco stalks; as emulsifyingand/or foam-forming agents there are suitable: for example non-ionic andanionic emulsifiers, such as polyoxyethylene fatty acid esters,polyoxyethylene fatty alcohol ethers, for example alkylaryl polyglycolethers, alkylsulfonates, alkyl sulfates, arylsulfonates as well asalbumen hydrolysis products; as dispersing agents there are suitable:for example lignin-sulfite waste liquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, as well as naturalphospholipids, such as cephalins and lecithins, and syntheticphospoholipids, can be used in the formulations. Other additives can bemineral and vegetable oils.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs and metal phthalocyaninedyestuffs, and trace nutrients such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain between 0.1 and 95 percent by weightof active compound, preferably between 0.5 and 90%.

The active compounds according to the invention can be present in theircommercially available formulations and in the use forms, prepared fromthese formulations, as a mixture with other active compounds, such asinsecticides, attractants, sterilizing agents, acaricides, nematicides,fungicides, growth-regulating substances or herbicides. The insecticidesinclude, for example, phosphates, carbamates, carboxylates, chlorinatedhydrocarbons, phenylureas and substances produced by microorganisms,inter alia.

The following compounds may be mentioned: Acrinathrin, alphamethrin,betacyfluthrin, bifenthrin, brofenprox, cis-resmethrin, clocythrin,cycloprothrin, cyfluthrin, cyhalothrin, cypermethrin, deltamethrin,esfenvalerate, etofenprox, fenpropathrin, fenvalerate, flucythrinate,fluvalinate, lambda-cyhalothrin, permethrin, pyresmethrin, pyrethrum,silafluofen, tralomethrin, zetamethrin.

Alanycarb, bendiocarb, benfuracarb, bufencarb, butocarboxim, carbaryl,cartap, ethiofencarb, fenobucarb, fenoxycarb, isoprocarb, methiocarb,methomyl, metolcarb, oxamyl, pirimicarb, promecarb, propoxur, terbam,thiodicarb, thiofanox, trimethacarb, XMC, xylylcarb,

acephate, azinphos A, azinphos M, bromophos A, cadusafos,carbophenothion, chlorfenvinphos, chlormephos, chlorpyrifos,chloropyrifos M, cyanophos, demeton M, demeton-S-methyl, demeton S,diazinon, dichlorvos, dicliphos, dichlorfenthion, dicrotophos,dimethoate, dimethylvinphos, dioxathion, disulfoton, edifenphos, ethion,etrimphos, fenitrothion, fenthion, fonophos, formothion,

heptenophos, iprobenfos, isazophos, isoxathion, phorate, malathion,mecarbam, mevinphos, mesulfenphos, methacrifos, methamidophos, naled,omethoate, oxydemeton M, oxydeprofos, parathion A, parathion M,phenthoate, phorate, phosalone, phosmet, phosphamidon, phoxim,pirimiphos A, pirimiphos M, propaphos, prothiophos, prothoate,pyraclophos, pyridaphenthion, quinalphos, salithion, sebufos, sulfotep,sulprofos, tetrachlorvinphos, temephos, thiomethon, thionazin,trichlorfon, triazophos, vamidothion,

buprofezin, chlorfluazuron, diflubenzuron, flucycloxuron, flufenoxuron,hexaflumuron, pyriproxifen, tebufenozide, teflubenzuron, triflumuron,

imidacloprid, nitenpyram,N-[(6-chloro-3-pyridinyl)-methyl]-N'-cyano-N-methyl-ethaneimideamide(NI-25),

abamectin, amitrazin, avermectin, azadirachtin, bensultap, Bacillusthuringiensis, cyromazine, diafenthiuron, emamectin, ethofenprox,fenpyrad, fipronil, flufenprox, lufenuron, metaldehyd, milbemectin,pymetrozine, tebufenpyrad, triazuron,

aldicarb, bendiocarb, benfuracarb, carbofuran, carbosulfan,chlorethoxyfos, cloethocarb, disulfoton, ethophrophos, etrimphos,fenamiphos, fipronil, fonofos, fosthiazate, furathiocarb, HCH,isazophos, isofenphos, methiocarb, monocrotophos, nitenpyram, oxamyl,phorate, phoxim, prothiofos, pyrachlofos, sebufos, silafluofen,tebupirimphos, tefluthrin, terbufos, thiodicarb, thiafenox,

azocylotin, butylpyridaben, clofentezine, cyhexatin, diafenthiuron,diethion, emamectin, fenazacluin, fenbutatin oxide, fenothiocarb,fenpropathrin, fenpyrad, fenpyroximate, fluazinam, fluazuron,flucycloxuron, flufenoxuron, fluvalinate, fubfenprox, hexythiazox,ivemectin, methidathion, monocrotophos, moxidectin, naled, phosalone,profenofos, pyraclofos, pyridaben, pyrimidifen, tebufenpyrad,thuringiensin, triarathene and4-bromo-2-(4-chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile(AC 303630).

The active compounds according to the invention can furthermore bepresent in their commercially available formulations and in the useforms, prepared from these formulations, as a mixture with synergisticagents. Synergistic agents are compounds which increase the action ofthe active compounds, without it being necessary for the synergisticagent added to be active itself.

The active compound content of the use formed prepared from thecommercially available formulations can vary within wide limits. Theactive compound concentration of the use forms can be from 0.0000001 to95% by weight of active compound, preferably between 0.0001 and 1% byweight.

The compounds are employed in a customary manner appropriate for the useforms.

The active compounds according to the invention are not only activeagainst plant, hygiene and stored product pests, but also, in theveterinary medicine sector, against animal parasites (ectoparasites andendoparasites) such as scaly ticks, Argasidae, scab mites, Trombidae,flies (stinging and sucking), parasitic fly larvae, lice, hair lice,bird lice, fleas and endoparasitic worms. For example, they have anoutstanding activity against ticks, such as, for example, Boophilusmicroplus.

The active compounds of the formula (I) according to the invention arealso suitable for combating arthropods which attack agriculturallivestock such as, for example, cattle, sheep, goats, horses, pigs,donkeys, camels, buffalo, rabbits, chickens, turkeys, ducks, geese,honey bees, other domestic animals such as, for example, dogs, cats,cage birds, aquarium fish and so-called experimental animals such as,for example, hamsters, guinea pigs, rats and mice. By combating thesearthropods, it is intended to reduce deaths and decreased performance(meat, milk, wool, hides, eggs, honey and the like), so that moreeconomical and simpler animal keeping is made possible by using theactive compounds according to the invention.

The application of the active compounds which can be used according tothe invention occurs in the veterinary sector in a known fashion byenteral application in the form of, for example, tablets, capsules,potions, drenches, granules, pastes, boli, by the feed-through method,by means of suppositories, by means of parenteral application in theform, for example, of injections (intramuscular, subcutaneous,intravenous, interperitoneal and the like), implants, by nasalapplication, by dermal administration, for example in the form ofdipping or bathing, spraying, pouring-on, spotting-on, washing, dusting,and with the aid of molded articles which contain active compound, suchas collars, ear tags, tail cuffs, limb bands, halters, marking devicesand the like.

The preparation and use of the substances according to the inventionwill be explained with reference to the examples below.

PREPARATION EXAMPLES Example I-1 ##STR97##

6.0 g (0.015 mol) ofO-(2,6-difluoro-benzoyl)-4-n-heptyl-phenoxy-acetamide oxime are heatedin 10 ml of glacial acetic acid until cyclization is complete(approximately 1 hour). The entire reaction mixture is then concentratedin vacuo, the product is taken up in ethyl acetate and washed withwater, and the organic phase is dried over sodium sulfate. The solventis subsequently distilled off in vacuo, and the crude product whichremains is chromatographed over a silica gel column (silica gel Merck,particle size: 0.040 to 0.063 mm) using cyclohexane:ethyl acetate (6:1)as the eluent.

1.8 g (31.1% of theory) of3-(4-n-heptyl-phenoxymethyl)-5-(2,6-difluorophenyl)-1,2,4-oxadiazole areobtained as an oil.

¹ H NMR (400 MHz, CDCl₃, δ): 0.67-1.54 (3 m, 15H, --C₇ H₁₅); 5.28 (s,2H, --O--CH₂ --); 6.96-7.59 (4 m, 7H, arom. H) ppm

Example I-2 ##STR98##

7.0 g (0.028 mol) of 4-(4-trifluoromethyl-phenoxy)-phenol are introducedinto 100 ml of acetonitrile, 7.7 g (0.056 mol) of potassium carbonateand 6.5 g (0.028 mol) of3-chloromethyl-5-(2,6-difluoro-phenyl)-1,2,4-oxadiazole are added, andthe mixture is stirred for approximately 12 hours at reflux temperature.The potassium chloride which has precipitated is then removed, and theentire reaction batch is concentrated in vacuo. The crude product whichremains can be recrystallized from isopropanol.

6.6 g (52.3% of theory) of3-[4-(4-trifluoromethyl-phenoxy)-phenoxy-methyl]-5-(2,6-difluoro-phenyl)-1,2,4-oxadiazoleof melting point 83-84° C. are obtained.

The compounds of the formula (I) which are listed in Table 11 below canbe prepared analogously and following the general preparationinstructions.

                                      TABLE 11                                    __________________________________________________________________________    Compounds of the formula (I)                                                                                        (I)                                     5 #STR99##                                                                    Ex. No.                                                                          X A        R.sup.3                                                                         2 #STR100##        Physical constants                         __________________________________________________________________________    I-3                                                                              O                                                                               6 #STR101##                                                                            H                                                                               8 #STR102##        m.p.: 46-48° C.                     I-4                                                                              O                                                                               7 #STR103##                                                                            H                                                                               8 #STR104##        m.p.: 46-47° C.                     I-5                                                                              O                                                                               6 #STR105##                                                                            H                                                                               9 #STR106##        m.p.: Oil                                  I-6                                                                              O                                                                               6 #STR107##                                                                            H                                                                               0 #STR108##        m.p.: Oil                                  I-7                                                                              O                                                                               6 #STR109##                                                                            H                                                                               2 #STR110##        m.p.: Oil                                  I-8                                                                              O                                                                               1 #STR111##                                                                            H                                                                               3 #STR112##        m.p.: 122° C.                       I-9                                                                              O                                                                               1 #STR113##                                                                            H                                                                               4 #STR114##        m.p.: 44-45° C.                     I-10                                                                             O                                                                               1 #STR115##                                                                            H                                                                               5 #STR116##        Oil                                        __________________________________________________________________________

Preparation of the starting substances

Example (II-1) ##STR117##

30.6 g (0.13 mol) of 4-n-heptyl-phenoxy-acetonitrile, 18.1 g (0.26 mol)of hydroxylamine hydrochloride and 27.6 g (0.26 mol) of sodium carbonateare stirred at reflux temperature in 100 ml of ethanol and 200 ml ofwater until the reaction is complete (approximately 24 hours). Theentire reaction batch is subsequently introduced into water, and themixture is extracted using methylene chloride. 34.3 g (99.8% of theory)of 4-n-heptyl-phenoxy-acetamide oxime are obtained.

¹ H NMR (400 MHz, CDCl₃, δ): 0.67-1.53 (3 m, 15H, --C₇ H₁₅); 4.54 (s,2H, --O--CH₂ --); 4.93 (br. s, 2H, --NH₂); 6.75-7.25 (4d, 4H, arom. H)ppm

The compounds of the formula (II) listed in Table 12 below can beprepared analogously and following the general preparation instructions.

                                      TABLE 12                                    __________________________________________________________________________    Compounds of the formula (II)                                                                                         (II)                                  1 #STR118##                                                                   Ex. No.                                                                           X R.sup.3                                                                         R.sup.4                                                                         2 #STR119##        Physical constants                               __________________________________________________________________________    II-2                                                                              O H H                                                                               3 #STR120##        4.36 (s, 2H, --O--CH.sub.2 --).sup.a) 5.57                                    (br. s, 2H, --NH.sub.2)                          II-3                                                                              O H H                                                                               4 #STR121##        4.56 (s, 2H, --O--CH.sub.2 --).sup.b) 4.98                                    (br. s, 2H, --NH.sub.2)                          II-4                                                                              O H H                                                                               5 #STR122##        4.53 (s, 2H, --O--CH.sub.2 --).sup.a) 4.96                                    (br. s, 2H, --NH.sub.2)                          __________________________________________________________________________     .sup.a)1 H NMR (400 MHz, CDCl.sub.3, δ) in ppm;                         .sup.b)1 H NMR (400 MHz, DMSOd.sub.6, δ) in ppm                    

Example (VI-1) ##STR123##

10.0 g (0.038 mol) of 4-n-heptyl-phenoxy-acetamide oxime and 10 ml ofpyridine are introduced into 100 ml of chloroform, and 7.4 g (0.042 mol)of 2,6-difluorobenzoyl chloride are added dropwise at 0° C. to 5° C.After the mixture has been stirred for approximately twelve hours atroom temperature, it is filtered, and the entire reaction batch isconcentrated in vacuo. The reaction batch is subsequently treated withwater, and the solid which separates out is filtered off with suction.

After recrystallization from diisopropyl ether, 7.0 g (46.9% of theory)of O-(2,6-difluorobenzoyl)-4-n-heptyl-phenoxy-acetamide oxime of meltingpoint 99-100° C. are obtained.

The compounds of the formula (VI) listed in Table 13 below can beprepared analogously.

                                      TABLE 13                                    __________________________________________________________________________    Compounds of the formula (VI)                                                                                                (IV)                           6 #STR124##                                                                   Ex. No.                                                                            X                                                                               7 #STR125##                                                                            R.sup.3                                                                          R.sup.4                                                                          2 #STR126##        Physical constants                   __________________________________________________________________________    VI-2 O                                                                               8 #STR127##                                                                            H  H                                                                                9 #STR128##        m.p.: 84-86° C.               VI-3 O                                                                               0 #STR129##                                                                            H  H                                                                                3 #STR130##        m.p.: 140-141° C.             VI-4 O                                                                               1 #STR131##                                                                            H  H                                                                                3 #STR132##        m.p.: 139-140° C.             VI-5 O                                                                               8 #STR133##                                                                            H  H                                                                                3 #STR134##                                             VI-6 O                                                                               0 #STR135##                                                                            H  H                                                                                5 #STR136##        m.p.: 89-90° C.               VI-7 O                                                                               8 #STR137##                                                                            H  H                                                                                5 #STR138##        m.p.: 94-96° C.               VI-8 O                                                                               1 #STR139##                                                                            H  H                                                                                5 #STR140##        m.p.: 143° C.                 VI-9 O                                                                               0 #STR141##                                                                            H  H                                                                                4 #STR142##        m.p.: 122-124° C.             VI-10                                                                              O                                                                               8 #STR143##                                                                            --H                                                                              --H                                                                              4 #STR144##        m.p.: Oil                            __________________________________________________________________________

Preparation of the precursors (VII)

Example (VII-1) ##STR145##

8.0 g (0.03 mol) of O-(2,6-difluoro-benzoyl-chloroacetamide oxime areheated in 16 ml of glacial acetic acid until cyclization is complete(approximately 2.5 hours). The entire reaction mixture is thenconcentrated in vacuo, the product is stirred with approximately 400 mlof water, and the mixture is subsequently extracted using methylenechloride. The organic phase is dried over sodium sulfate, and thesolvent is distilled off in vacuo. The crude product which remains ischromatographed over a silica gel column (silica gel 60-Merck, particlesize: 0.040 to 0.063 mm) using toluene:methanol (9:1) as the eluent. 3.4g (49.1% of theory) of3-chloromethyl-5-(2,6-difluoro-phenyl)-1,2,4-oxadiazole of melting pointm.p.: 33-34° C. are obtained. ##STR146##

21.4 g (0.2 mol) of chloroacetamide oxime and 19.4 g (0.2 mol) oftriethylamine are introduced into 100 ml of 1,4-dioxane, and 34.6 g (0.2mol) of 2,6-difluoro-benzoyl chloride are added dropwise with cooling.After stirring has been continued at room temperature for approximatelytwo hours, the entire reaction batch is poured into 400 ml of water, andthe solid which separates out is filtered off with suction. Afterrecrystallization from methanol, 15.3 g (32.4% of theory) ofO-(2,6-difluoro-benzoyl)-chloroacetamide oxime of melting point 100-101°C. are obtained.

O-(2,6-Dichloro-benzoyl)-chloroacetamide oxime of melting point 133-134°C. is obtained analogously.

Example (IX-1) ##STR147##

18.8 g (0.074 mol) of 4-(4-trifluoromethyl-phenoxy)-phenol and 10.2 g(0.074 mol) of potassium carbonate are introduced into 100 ml ofacetone, 5.0 g (0.067 mol) of chloroacetonitrile are added in portions,and the mixture is stirred for 6 hours at reflux temperature. Aftercooling, the mixture is poured into water and extracted using ether. Theorganic phase is separated off, dried over magnesium sulfate andconcentrated in vacuo.

18.8 g (86.6% of theory) of4-(4-trifluoromethyl-phenoxy)-phenoxy-acetonitrile are obtained.

The compounds of the formula (IX) listed in Table 14 below can beprepared analogously.

                                      TABLE 14                                    __________________________________________________________________________    Compounds of the formula (IX)                                                 2 #STR148##                                                                   Ex. No.                                                                            X R.sup.2                                                                         R.sup.3                                                                         2 #STR149##     Physical constants                                 __________________________________________________________________________    IX-2 O H H                                                                               3 #STR150##     4.73 (s, 2H, --O--CH.sub.2 --).sup.a)              IX-3 O H H                                                                               4 #STR151##     4.73 (s, 2H, --O--CH.sub.2 --).sup.a)              IX-4 O H H                                                                               3 #STR152##     4.71 (s, 2H, --O--CH.sub.2 --).sup.a)              __________________________________________________________________________     .sup.a)1 H NMR (400 MHz, CDCl.sub.3, δ) in ppm                     

Example A

Tetranychus test (OP resistant/spray treatment)

Solvent: 3 parts by weight of dimethylformamide

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent and thestated amount of emulsifier, and the concentrate is diluted withemulsifier-containing water to the desired concentrations.

Bean plants (Phaseolus vulgaris) which are severely infested with allstages of the greenhouse red spider mite (Tetranychus urticae) aresprayed with a preparation of active compound of the desiredconcentration.

After the specified periods of time, the activity in % is determined.100% means that all the spider mites have been killed; 0% means thatnone of the spider mites have been killed.

In this test, a degree of destruction of at least 95% at an exemplaryactive compound concentration of 0.1% is shown after 7 days for exampleby the compounds of Preparation Examples I-1, I-2, I-4, I-5, I-7, I-8,I-9, I-10, (VI-6), (VI-7), (VI-9) and (VI-10).

Example B

Phaedon larvae test

Solvent: 7 parts by weight of dimethylformamide

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent and thestated amount of emulsifier, and the concentrate is diluted withemulsifier-containing water to the desired concentrations.

Cabbage leaves (Brassica oleracea) are treated by being dipped into thepreparation of the active compound of the desired concentration and areinfested with mustard beetle larvae (Phaedon cochleariae) while theleaves are still moist.

After the specified periods of time, the destruction in % is determined.100% means that all the beetle larvae have been killed, 0% means thatnone of the beetle larvae have been killed.

In this test, a degree of destruction of 100% at an exemplary activecompound concentration of 0.1% is shown after 7 days for example by thecompound of Preparation Example I-6.

Example C

Panonychus test

Solvent: 3 parts by weight of dimethylfomamide

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent and thestated amount of emulsifier, and the concentrate is diluted withemulsifier-containing water to the desired concentrations.

Plum trees (Prunus domestica) approximately 30 cm high which areseverely infested with all stages of the fruit tree red spider mitePanonychus ulmi are sprayed with a preparation of active compound of thedesired concentration.

After the specified periods of time, the destruction in % is determined.100% means that all the spider mites have been killed, 0% means thatnone of the spider mites have been killed.

In this test, a degree of destruction of at least 95% at an exemplaryactive compound concentration of 0.02% is shown after 7 days for exampleby the compounds of Preparation Examples I-1, I-2, I-4 and I-5.

Example D

Fly test (Musca domestica)

Test animals: Musca domestica adults, strain Reichswald (OP, SP,carbamate resistant)

Solvent: 35 parts by weight of ethylene glycol monomethyl ether 35 partsby weight of nonylphenol poly-glycol ether.

To produce a suitable formulation, 3 parts by weight of active compoundare diluted with 7 parts of the above-mentioned solvent/emulsifiermixture and the emulsion concentrate thus obtained is diluted with waterto the particular desired concentration.

2 ml of this preparation of active compound are pipetted onto filterpaper disks (φ9.5 cm) in Petri dishes of an appropriate size. After thefilter paper has dried, 25 test animals are introduced into the Petridishes and covered.

After 1, 3, 5 and 24 hours, the effectiveness of the preparation ofactive compound is determined. 100% means that all of the f lies havebeen killed, 0% means that no flies have been killed.

In this test, a degree of destruction of 100% at an exemplary activecompound concentration of 1000 ppm is shown, for example, by thecompound of Preparation Example (VII-1).

Example E

Plutella test

Solvent: 7 parts by weight of dimethylformamide

Emulsifier: 1 part by weight of alkylaryl polyglycol ether.

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent and thestated amount of emulsifier, and the concentrate is diluted with waterto the desired concentration.

Cabbage leaves (Brassica oleracea) are treated by being dipped into thepreparation of active compound of the desired concentration and areinfested with caterpillars of the diamond-back moth (Plutellamaculipennis) while the leaves are still moist.

After the specified periods of time, the destruction in % is determined.100% means that all the caterpillars have been killed; 0% means thatnone of the caterpillars have been killed.

In this test, a degree of destruction of 100% at an exemplary activecompound concentration of 0.1% is shown after 7 days for example by thecompound of Preparation Example I-3.

We claim:
 1. A 1,2,4-oxadiazole derivative of the formula ##STR153## inwhich R¹ represents halogen, alkyl or alkoxy,R² represents hydrogen,halogen, halogenoalkyl or halogenoalkoxy, R³ represents hydrogen oralkyl, R⁴ represents hydrogen or alkyl, R⁵ represents halogen,trialkylsilylalkyl, trialkylsilylalkoxy; or a group --A_(k) --R⁷ inwhichA represents oxygen, sulfur, SO, SO₂, alkylene, alkyleneoxy,alkylenethio, oxyalkylene, oxyalkyleneoxy, alkyleneoxyalkylene,alkenediyl or alkindiyl, k represents a number 0 or 1, R⁷ representsalkyl, halogenoalkyl, alkenyl, halogenoalkenyl, alkinyl,halogenoalkinyl, optionally substituted cycloalkyl, optionallysubstituted phenyl or optionally substituted pyridyl, or R⁵ representsoptionally substituted cycloalkyl, it being possible for one or two CH₂groups which are not bonded directly to each other to be replaced byoxygen and/or sulfur, R⁶ represents hydrogen, halogen, alkyl,halogenoalkyl, alkoxy or halogenoalkoxy, m represents a number 1, 2 or3, n represents a number 1, 2 or 3, X represents O, S, SO, SO₂, CH₂ or agroup N--R⁸ in whichR⁸ represents hydrogen or alkyl and Y represents anitrogen atom or the group C--R⁹ in whichR⁹ represents hydrogen, halogenor alkyl; with the exception of thecompounds:5-(4-chlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazoleand5-(2,4-dichlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazoleand3-(4-tert-butyl-phenoxymethyl)-5-(2,6-difluorophenyl)-1,2,4-oxadiazole2. A compound according to claim 1 of the formula ##STR154## in which Arepresents one of the radicals listed below ##STR155## B represents oneof the radicals ##STR156## R³ represents hydrogen or methyl, Xrepresents CH₂, O, S, SO or SO₂ andR⁵ has the meaning given in claim 1.3. A 1,2,4-oxadiazole derivatives according to claim 1, in whichR¹represents fluorine, chlorine, bromine, C₁ -C₆ -alkyl or C₁ -C₆ -alkoxy,R² represents hydrogen, fluorine, chlorine, bromine, C₁ -C₆-halogenoalkyl or C₁ -C₆ -halogenoalkoxy, R³ represents hydrogen or C₁-C₄ -alkyl, R⁴ represents hydrogen or C₁ -C₄ -alkyl, R⁵ representsfluorine, chlorine, bromine, tri-(C₁ -C₈ -)-alkyl-silyl-(C₁ -C₆ -)-alkylor tri-(C₁ -C₈ -)-alkyl-silyl-(C₁ -C₆ -)-alkoxy, or a group --A_(k)--R⁷, in whichA represents oxygen, sulfur, SO, SO₂, C₁ -C₆ -alkylene, C₁-C₆ -alkyleneoxy, C₁ -C₆ -alkylenethio, C₁ -C₆ -oxyalkylene, C₁ -C₆-oxyalkyleneoxy, C₁ -C₆ -alkyleneoxy-C₁ -C₆ -alkylene, C₂ -C₅-alkenediyl or C₂ -C₅ -alkindiyl, k represents a number 0 or 1 and R⁷represents C₁ -C₂₀ -alkyl, C₂ -C₂₀ -alkenyl or C₂ -C₂₀ -alkinyl, each ofwhich is optionally monosubstituted or polysubstituted by fluorineand/or chlorine, or represents C₃ -C₁₂ -cycloalkyl which is optionallymonosubstituted to trisubstituted by identical or different substituentsand in which one or two CH₂ groups which are not directly adjacent areoptionally replaced by oxygen and/or sulfur, or phenyl which isoptionally monosubstituted to pentasubstituted by identical or differentsubstituents or pyridyl which is optionally monosubstituted totrisubstituted by identical or different substituents, whereincycloalkyl, phenyl or pyridyl substituents arehalogen, C₁ -C₁₈ -alkyl,C₁ -C₈ -alkoxy-C₁ -C₈ -alkyl, C₁ -C₈ -halogenoalkoxy, C₁ -C₄-halogenoalkyl, C₁ -C₁₈ -alkoxy which is optionally interrupted by afurther 1-3 oxygen atoms, C₁ -C₁₈ -alkylthio, C₁ -C₈ -halogenoalkylthio,3. 4-difluoromethylene dioxo,3,4-tetrafluoroethylene dioxo,benzyliminooxymethyl which is optionally substituted by C₁ -C₄ -alkyl,C₃ -C₆ -cycloalkyl and/or halogen, cyclohexyl and cyclohexyloxy, each ofwhich is optionally substituted by C₁ -C₆ -alkyl, C₁ -C₆ -alkoxy,cyclohexyl and/or phenyl; pyridyloxy which is optionally monosubstitutedor disubstituted by identical or different substituents selected fromthe group consisting of halogen, C₁ -C₄ -alkyl or C₁ -C₄ halogenoalkyl;phenyl, benzyl, phenoxy, phenylthio, benzyloxy and benzylthio, each ofwhich is optionally monosubstituted or disubstituted by identical ordifferent substituents selected from the group consisting of C₁ -C₁₂-alkyl, halogen, C₁ -C₄ -halogenoalkyl, C₁ -C₆ -alkoxy, C₁ -C₆-halogenoalkoxy, C₁ -C₆ -alkoxy-C₁ -C₆ -alkyl, C₁ -C₆-alkoxy-ethyleneoxy, C₁ -C₆ -alkylthio or C₁ -C₆ -halogenoalkylthio; orR⁵ represents optionally substituted C₃ -C₁₀ -cycloalkyl in which one ortwo CH₂ groups which are not directly linked to each other are replacedby oxygen and/or sulfur, wherein the substituents are the cycloalkylsubstituents mentioned in the case of R⁷, R⁶ represents hydrogen,fluorine, chlorine, bromine, C₁ -C₈ -alkyl, C_(l) -C₈ -halogenoalkyl, C₁-C₈ -alkoxy or C₁ -C₈ -halogenoalkoxy, m represents a number 1, 2 or 3,n represents a number 1, 2 or 3, X represents O, S, SO, SO₂, CH₂ or thegroup NH or N--CH₃, Y represents nitrogen or the group --CR⁹ in whichR⁹represents hydrogen, fluorine, chlorine, bromine or C₁ -C₆ -alkyl,withthe exception of the compounds5-(4-chlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazole and5-(2,4-dichlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazoleand3-(4-tert-butyl-phenoxymethyl)-5-(2,6-difluorophenyl)-1,2,4-oxadiazole.4. A 1,2,4-oxadiazole derivative according to claim 1, in whichR¹represents fluorine, chlorine, bromine, C₁ -C₄ -alkyl or C₁ -C₄ -alkoxy,R² represents hydrogen, fluorine, chlorine, bromine, C₁ -C₄-halogenoalkyl or C₁ -C₄ -halogenoalkoxy, R³ represents hydrogen ormethyl, R⁴ represents hydrogen or methyl, R⁵ represents fluorine,chlorine, bromine, trimethylsilylmethyl, trimethylsilylmethoxy,dimethylethylsilylmethyl, dimethylethylsilylmethoxy,butyldimethylsilylmethyl, butyldimethylsilylmethoxy or a group --A_(k)--R⁷ in whichA represents oxygen, sulfur, SO, SO₂ or C₁ -C₄ -alkylene,C₁ -C₄ -alkyleneoxy, C₁ -C₄ -alkylenethio, C₁ -C₄ -oxyalkylene, C₁ -C₄-oxyalkyleneoxy, C₁ -C₄ -alkyleneoxy-C₁ -C₄ -alkylene, in particular--CH₂ --, --CH₂ CH₂ --, --CH(CH₃)--, --CH₂ CH₂ CH₂ --, --CH(CH₃)CH₂ --,--C(CH₃)₂ --, --CH₂ CH₂ CH₂ CH₂ --, --CH(CH₃)CH₂ CH₂ --, --CH₂CH(CH₃)CH₂ --, --CH₂ O--, --CH₂ CH₂ O--, --CH(CH₃)O--, --CH₂ CH₂ CH₂O--, --CH(CH₃)CH₂ O--, --C(CH₃)₂ O--, --CH₂ CH₂ CH₂ CH₂ O--,--CH(CH₃)CH₂ O--, --CH₂ CH(CH₃)CH₂ O--, --OCH₂ --, --CH₂ S--, --OCH₂ CH₂--, --OCH(CH₃)--, --OCH₂ CH₂ CH₂ --, --OCH(CH₃)CH₂ --, --OC(CH₃)₂ --,--OCH₂ CH₂ CH₂ CH₂ --, --OCH(CH₃)CH₂ CH₂ --, --OCH₂ CH(CH₃)CH₂ --; --CH₂OCH₂ --, --CH₂ SCH₂ --, --CH₂ OCH₂ CH₂ --, --OCH₂ O--, --OCH₂ CH₂ O--,--OCH(CH₃)O--, --OCH₂ CH₂ CH₂ O--, OCH(CH₃)CH₂ O--, --OC(CH₃)₂ O--,--OCH₂ CH₂ CH₂ CH₂ O--, --OCH(CH₃)CH₂ CH₂ O--, --CH₂ CH(CH₃)CH₂ O--, C₂-C₅ -alkenediyl or C₂ -C₅ -alkindiyl, k represents a number 0 or 1, R⁷represents C₂ -C₂₀ -alkyl, C₂ -C₂₀ -alkenyl or C₁ -C₂₀ -alkinyl and eachof which is optionally monosubstituted or polysubstituted by fluorineand/or chlorine, C₃ -C₁₀ -cycloalkyl which is optionally monosubstitutedto trisubstituted by identical or different substituents, phenyl whichis optionally monosubstituted to pentasubstituted by identical ordifferent substituents or pyridyl which is optionally monosubstituted totrisubstituted by identical or different substituents, whereincycloalkyl, phenyl and pyridyl substituents areF, Cl, Br, C₁ -C₁₈-alkyl, C₁ -C₆ -alkoxy-C₁ -C₈ -alkyl, C₁ -C₈ -alkoxy which ismonosubstituted to hexasubstituted by identical or differentsubstituents selected from the group consisting of F and Cl, C₁ -C₂-alkyl which is monosubstituted to pentasubstituted by identical ordifferent substituents selected from the group consisting of F and Cl,C₁ -C₁₈ -alkoxy, (OCH₂ H₄)₁₋₃ --, O--C₁ -C₆ -alkyl, C₁ -C₁₂ -alkylthio,C₁ -C₈ -alkylthio which is monosubstituted to hexasubstituted byidentical or different substituents selected from the group consistingof F and Cl,
 3. 4-difluoromethylenedioxo,3,4-tetrafluoroethylenedioxo,the groups ##STR157## cyclohexyl, cyclohexyloxy, each of which isoptionally substituted by C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy, cyclohexyl orphenyl; pyridyloxy which is optionally monosubstituted or disubstitutedby identical or different substituents selected from the groupconsisting of F, Cl and CF₃, phenyl, benzyl, phenoxy, phenylthio,benzyloxy and benzylthio, each of which is optionally monosubstituted ordisubstituted by identical or different substituents selected from thegroup consisting of C₁ -C₁₂ -alkyl, F, Cl, Br, CF₃, C₁ -C₄ -alkoxy, C₁-C₄ -alkoxy which is monosubstituted to hexasubstituted by identical ordifferent substituents selected from the group consisting of F and Cl,C₁ -C₄ -alkoxy-C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy-ethyleneoxy, C₁ -C₄-alkylthio or C₁ -C₄ -alkylthio which is monosubstituted tohexasubstituted by identical or different substituents selected from thegroup consisting of F and Cl, or R⁵ represents optionally substituted C₃-C₈ -cycloalkyl in which one or two CH₂ groups which are not linked toeach other are replaced by oxygen and/or sulfur, wherein thesubstituents are those mentioned in the case of R⁷, R⁶ representshydrogen, fluorine, chlorine, bromine, C₁ -C₆ -alkyl, C₁ -C₆-halogenoalkyl, C₁ -C₆ -alkoxy or C₁ -C₆ -halogenoalkoxy, m represents anumber 1, 2 or 3, n represents a number 1 or 2, X represents O, S, SO,SO₂, CH₂ or the group NH or N--CH₃, Y represents a nitrogen atom or thegroup --CR⁹ in whichR⁹ represents hydrogen, fluorine, chlorine, bromineor C₁ -C₆ -alkyl, with the exception of thecompounds:5-(4-chlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazoleand5-(2,4-dichlorophenyl)-3-[2-(2,4-dichlorophenyl)ethyl]-1,2,4-oxadiazoleand3-(4-tert-butyl-phenoxymethyl)-5-(2,6-difluorophenyl)-1,2,4-oxadiazole.5. A 1,2,4-oxadiazole derivative according to claim 1, wherein X is O,SO, SO₂, CH₂, or a group N--R⁸.
 6. A 1,2,4-oxadiazole derivativeaccording to claim 1, which has the formula ##STR158##
 7. A pesticidalcomposition which comprises an effective amount of a compound accordingto claim 1 and an inert carrier.
 8. A method of combatting animal pestswhich comprises applying an effective amount of a compound according toclaim 1 to said pests or to an environment where they reside.
 9. Aprocess for the preparation of 1,2,4-oxadiazole derivatives of theformula (I) as claimed in claim 1, wherein compounds of the formula (II)##STR159## in which n, X, R³, R⁴, R⁵ and R⁶ have the meanings given inclaim 1,are reacted with carboxylic acid derivatives of the formula(III), (IV) or (V) ##STR160## in which R¹, R², m and Y have the meaningsgiven in claim 1, R represents alkyl and Z represents a leaving group.10. A process for the preparation of pesticides, which comprises mixingcompounds of the formula (I) as claimed in claim 1 with extenders and/orsurfactants.